Selectable mode multipushbutton switch

ABSTRACT

A motor-driven appliance including a multipushbutton switch with permutatable control sliders and switches providing different speeds selectively in association with a mode control to provide either a continuous or a momentary run of the appliance when any of the speed selection pushbuttons is manually pressed. The mode control in one position returns the sliders to &#39;&#39;&#39;&#39;OFF&#39;&#39;&#39;&#39; position when a pushbutton is released that was being pressed, while in another position the sliders remain in a continuous run position when the pressed pushbutton is released. The mode is selected by varying the tension upon a spring which urges the return of sliders and pushbuttons to a predetermined position. The mode can be changed during operation of the liquidizer and can serve as a stop control.

United States Patent [54] SELECTABLE MODE MULTIPUSHBUTTON SWITCH 15Claims, 10 Drawing Figs.

[52] U.S. Cl 318/252, 200/5 E, 318/305, 318/351, 318/424, 318/443 [51]1nt.Cl 1102p 7/10 [50] Field of Search 318/251,

[56] References Cited UNITED STATES PATENTS 2,831,075 4/1958 Dumke etal. 200/5 2,866,860 12/1958 Sharp et al 200/5 so u Primary Examiner-CrisL. Rader Assistant Examiner-K. L. Crosson Attorney-Harbaugh and ThomasABSTRACT: A motor-driven appliance including a multipushbutton switchwith permutatable control sliders and switches providing differentspeeds selectively in association with a mode control to provide eithera continuous or a momentary run of the appliance when any of the speedselection pushbuttons is manually pressed. The mode control in oneposition returns the sliders to OFF position when a pushbutton isreleased that was being pressed, while in another position the slidersremain in a continuous run position when the pressed pushbutton isreleased. The mode is selected by varying the tension upon a springwhich urges the return of sliders and pushbuttons to a predeterminedposition. The mode can be changed during operation of the liquidizer andcan serve as a stop control.

PATENTEUSEP28IE17I SHEET 1 0F 2 INVENTORS: ROY L. SWAN/(E BRUNO MVALBONA BJVM%I 0%,4 Afforneys PAIENTED S EP28 IQII 3; 09,491

' SHEET 2 OF 2 SPEEDS COILS SWITCHES OFF 0 s I ABCD 2s 2 ABC 24 3 AC I44 -g-(: I34 I l\\\\ C 56 5 K49 5 AB- 2467 7 l I I346? FIG. 7

DI Di Di Bi c c A C COILS D ABCD ABC AC EC A85 A6 Di Di Di Di SPEEDS OFFl 2 3 4 5 7 SWITCHES s 25 24 I4 I34 246? I467 6391 SWITCH s00 STATIONS(I) (2) (3) (4) (5) (6) (7) (8) F I 6. I INVEN roRs:

R0) L. SWAN/(E BRUNO M. VAL BOIVA Q Attorneys SELECTABLE MODEMULTIPUSHBUTTON SWITCH CROSS-REFERENCE Swanke and Raymond, Ser. No. 8 I3,957 Kelley et al., filed Oct. 15, 1969 BACKGROUND OF THE INVENTIONAlthough definiteness of timing, agitation speeds and volumes ofingredients have become increasingly important in recipes and formulasfor desired optimum results when ingredients are being comminuted,mixed, homogenized or blended, generally referred to herein asliquidizing, occasion arises where the user, as a matter of economy orpersonal indulgence, or both, desires to use a liquidizer solely bymanual control either in a continuous run mode or momentary run mode toaccomplish particular results or vary them in accordance with the whimsor experiments of the user. In brief, the users very often like to trynew ideas and do things their own way with continuous run and momentaryrun modes actually at their fingertips.

SUMMARY OF THE INVENTION In the present invention at least seven speedsin an eightpushbutton permutatable slider switch are provided incombination with a diode forsome of the speeds and each of these speedsare selectively available for either sustained operation or momentaryoperation of a liquidizer, a word used here to include blending,chopping, homogenizing and pulverizing with rotating blades.

The operation or mode of controlling a multipushbutton appliance isprovided by the embodiment of the invention wherein any speed selectorpushbutton can be pressed and released for a run that is continuousuntil another control such as an OFF pushbutton is manually actuated, orthe run continues only while a pushbutton is being pressed.

For the OFF condition the permutations of switch control slidersincludes a position where the sliders are brought to a particularrelationship for the speed control switches. This permutation can beattained selectively in several ways, by pressing either an OFFpushbutton or changing the mode selector control, or by releasing aspeed change pushbutton that has been held finger pressed during amomentary run mode setting.

In attaining the OFF position one or more sliders are selectivelyactuated to open a significant switch or switch combination, and, such aswitch or switch combination can be either a main switch or one or morespeed control switches. The selector for the alternative modes ofoperating contemplates a resilient force, preferably a spring whosetension is selectively applied to or removed from the sliders. In onemode the tension when applied returns one or more sliders to their OFFposition as indicated, and also the released pushbutton is returned toits resting or open position. In the other mode when the tension isabsent or removed, a speed selector pushbutton when depressed willremain to energize the appliance until the OFF pushbutton is pressed, orthe spring tension is applied.

Two embodiments are illustrative of the inventive concept asaccomplished either by a resilient control of a single slider or of allsliders.

In the use of one slider it may be a slider devoted either to thecontrol of a main switch which is closed by any of the speed selectionpushbuttons, or by the applied spring tension when a speed selectionbutton being manually depressed is released. When more than one slideris employed the resilient pressure can be applied to urge sliders in onedirection to a position in which a critical speed selection switch isopened to serve as an OFF switch. The appliance can be operated in thesemodes and changes made at any selected speed.

It will be appreciated that for purposes of economy the speed selectionswitches may be of light material rated for current carrying servicealone while a heavy main switch rated for make-and-break operationmomentarily opens and closes during speed change-switching.

DESCRIPTION OF DRAWINGS FIG. I is a perspective view of a liquidizer andcontrols therefor embodying the invention including a multiplepushbutton switch for providing different speeds for selectivecontinuous run or momentary run with the same pushbuttons and speedscontrolled thereby;

FIG. 2 is a bottom perspective view of the two main housing parts of theembodiment shown in FIG. 1, with the bottom cover partially cut away toshow the components mounted on the control panel;

FIGS. 3 and 4 are enlarged fragmentary elevational views of thepushbutton, push rod, slider and switch constructions and cooperationembodied in the present invention;

FIG. 5 is an electrical schematic of a representative circuit embodiedin the present invention;

FIG. 6 is a chart showing a speed control arrangement in which thecircuit shown in FIG. 5 is employed;

FIG. 7 is a composite expanded view showing the configuration of thespeed selector sliders of a pushbutton switch embodying the inventionimplementing the chart of FIG. 6 with respect to the schematic circuitof FIG. 5;

FIG. 8 is a perspective view of the working elements of the selector andthe preferred control by it of the pushbutton switches shown in FIG. 2;

FIG. 9 is a bottom plan view of the working elements of the selector andpushbutton switch according to another embodiment of the invention;

FIG. 10 is a plan view of an added slider modification of FIG. 7 inwhich an OFF switch slider is included in the pushbutton switchingpermutation for operation of FIG. 9.

DESCRIPTION OF EMBODIMENTS In FIG. 1, a liquidizer l0 embodying theinvention is shown which includes a container 12 of the well-knowncross-sectional cloverleaf design having a capacity, preferably of lessthan 2 quarts. The container is supported at its base against rotationin its working position within a collar 16 on a housing 14. Cutters (notshown) are rotatably mounted in the bottom wall of the container on ashaft journaled there as driven by a series-wound motor 22 throughdisengageable clutch elements. On the housing 14 an instrument panel 24is provided which carries a selector knob 26 and a multipushbuttonswitch 32 designed with eight pushbuttons 28. The switch 32 is mountedon the liquidizer panel 24 where it is protected by a bottom cover 34,with its pushbuttons 28 extending through the panel and duly labeled forconvenience as to function including an OFF button 30.

The general construction of the multiple switch is somewhat conventionalin that it has a hollow elongated housing 40 molded of suitableinsulating material defining a slider chest 45 which receives anassembly of switch-actuating sliders 48 (FIG. 5) in supportedrelationship for relative longitudinal reciprocation. Vertical push rods44 slidable in guideways 43 carry the push buttons 28 on their upperends and curled elements 47 on their lower ends to actuate the sliders48.

The switches 49 that are actuated by the sliders 48, as illustrated inFIG. 4, are located below the sliders and comprise a row of stationaryterminals 46 having downwardly facing fixed contacts 51. Along the otherside are other terminals 53 resiliently supporting one end of bridgingconductors 56 whose other ends provide contact areas 55 urged to closeagainst the fixed contacts 5! in an upward direction when free to do so.A flat cover plate 50 of insulating material is secured to the housing40 by suitable means to close the switch chamber with sufficientclearance to permit operation of the bridging conductors 56 and supportthe sliders with respect thereto as more particularly described inSwanke, Ser. No. 813,957.

All sliders 48 are made of insulating phenolic board and, as illustratedin FIG. 3, are supported by extensions 52 spaced along their lower edgesand slidably bearing against the cover plate 50 to carry the downwardthrust of the push rods 44 actuating them. Between successive extensions52 of the sliders have recesses 54 along the lower edges at each switchstation indicated by the conductor 56 and are provided with variousshapes including earns 58 to operate or not operate the con ductors astheir permutation requires. If a conductor 56 is to be actuated at aparticular recess, the recess is provided with a cam contour having ashort high-dwell 60 and a long low-dwell 62 separated by a cam incline64 which either closes the switch or opens it depending upon therelative location of the conductor and the direction of movement of theslider when actuated. Thus, when a switch 49 is open the correspondingrecesses 54 of the sliders are so arranged with respect to the switchconductors 56 that one or more high-dwells 60 of those present at thatstation engages the conductor to hold the switch open in a downwarddirection, and when a switch is to be closed the low-dwells 62 in allrecesses 54 at that station coincide to permit the resilient conductor56 to rise and close the contacts 51 and 52.

For permutation of the sliders 48 and thereby the switch closings, theupper edges of the sliders have notches 66 receiving the curled elements47 of the push rods 44. The notches generally define a vertical side 68and a side inclined thereto to provide a cam 70 actuated by a curledelement 47 for moving the slider in the direction indicated by thearrows. In FIG. 7 full sliders are shown as described along with arrowsto indicate the slider movement induced by the push rods at each notch62 station. I V

in FIG. 5 a circuit is shown for use with the switches. The particularswitches 49 are identified by numerals (l) to (8), the speeds bynumerals l to 7, and the field coils by letters A, C PQD- The fieldcoils are 120 turns each, of the wire gauges shown, A 029, B 024, C 025,and D 028. Each coil of the armature R has 55 turns of 028 gauge wire.The impedance provided by the respective coils is represented by thegauge size of the conventional copper field-coil wire employed in themas based upon their circular mils. WMWWD Coils A and B are cowound andcoils C and D are cowound for the respective poles for compactness ofsmaller wire nesting in the interstices of the turns in the larger wire.The switching for each pair of coils follows the same configuration inwhich switch (2) or (5) interconnects the coils in the respective pairsat their electrically adjacent ends for series connection; switch (3) or(6) interconnects the electrically leading ends of the paired coils tobridge coils A or C and switches (2) or (5) through connections 90 or92, respectively; and switch (1) or (5) interconnects the electricallytrailing ends of the paired coils to bridge coils B or D and switches(2) or (5) through connections 94 or 96, respectively. Connection 90 isconnected to one lead L of an AC power source and the other connection96 is connected to the other lead L through a switch (8), if used, thatis serially connected to a diode unit which includes a rectifier Di forhalf wave power and a switch (7) connected in parallel therewith,whereby the rectifier Di is shunted for full AC current when the switch(7) is closed. The connections 94 and 92 are connected to oppositeterminals of the a u sB- in the switching pattern one or more of theswitches are involved each time a speed is selected and can be handledby two permutation sliders for each pair of coils. The switch circuitpattern for both pairs are substantially the same and referring to onepair as representative of both, each pair can be controlled by twosliders 48 for four permutations each because switch (I) is never closedwith switch (2) and switch (2) is never closed with switch (3), butswitches (l) and (3) can be closed separately or together. W N

Referring for further particulars to sliders 48A and 488 asrepresentative of sliders 48C and 48D, slider 48A cams switches (l) and(3) open while closing switch (2) when moved in the direction indicatedby the left directed arrows thereon. When moved in the oppositedirection, indicated by right-directed arrows, switches (l) and (3) areclosed and switch (2) is opened. However, in cooperation with slider 48Aslider 483 will open switch (2) if otherwise closed and will open switch(3) if free to open when moved as indicated by left-directed arrows andwhen moved in the opposite direction, slider 488 will close switch (2)if free to close and will open switch (3) if otherwise closed. 'lhus,except when the slider 48A is moved to the right and the slider 48B ismoved to the left to close both switches (l) and (3), the other relativepositions provide a single closing of each of three switches. Thus, thefour permutations available with the three switches are 13, 1, 2, 3which in turn involves coils A/B, A, AB and B respectively. This issimilarly true for coils C and D and switches (5), (6) and (7). However,it is to be noted in this embodiment that a cam 60s is provided in therecess at switch station (3) which opens switch (3) when the sliders 48Aand 48B are both moved to the left to provide an open circuit conditioncontrolled by the OFF pushbutton or by the tension of the spring crank74 when applied as described.

Accordingly, the possible combinations of field coils A, B, C and D maybe permutated with increased low-speed increments in the low-speed rangein series with diode Di as shown in FIG. 7 following the words COlLS,namely, ABCD (series), ABC (series), AC (series) and C (parallelseries)according to the closing of the switches following the itation SW lTCHl3 8. l l igher speed coil combinations without the diode are AB C /D(series-parallel), A-C/D (series-parallel) and A/B C/D(parallel-parallel). The switches involved are also indicated followingthe notation wit he .7 WC- .3

The operation of the rectifier Di can be and is associated with thesliders 48C and 48D to close switch (7) at high speeds where only bothswitches (4) and (6) are closed in association with switch closures ofswitches (1), (2) or (3). Thus, the relative directional shifts of thesliders 48C and 48D can provide not only for the closure of switches (4)and (6) as part of the permutation, but also close the diode switch (7)by the use of high-dwells 60D shown on sliders 48C and 48D cooperatingwith the diode switch (7).

Although the OFF position of the sliders may involve closing switch (6)it will be observed that switches (l), (2) and (3) can be and are heldopen to open the motor circuit. This opening of switches (l), (2) and(3) is accomplished by moving all sliders to the left as indicated bythe arrows at the OFF button station.

in this connection reference is made to FIGS. 7 and 8 where the adjacentends of the sliders are coincidentally notched as at 72 to receive thecrank arm 74 ofa torque spring 76 that is pivotally mounted on theswitch housing 40 by a screw 78 at its bight. The crank arm is actuatedby the lever arm 80 portion of the spring and is controlled by a cam arm82 driven between two positions by the selector knob 26. In the manualposition indicated the lever and cam arms are in a relaxed position. Inthe jog position, in broken lines, the cam arm displaces the lever armwith approximately movement and this tensions the crank arm 72 to urgethe sliders to the left.

Thereby, for momentary energization of the liquidizer, the sliders willbe resiliently returned and held in their OFF permutation whenever adepressed speed selection pushbutton is not being manually helddepressed. When the switch (8) is present, as later described, thissequence of operation is related to the long low-dwells 62 in the sliderrecesses 54 at the speed selection switch stations (1) to (6) and theprotuberances 59 in the slider recesses at the switch (8) station.

Thereby the switch (8) may be one rated to take the surge of the makingand breaking of the load current while the permutation switches can beeconomically made of light material rated merely to carry the currentwhen closed. In this connection, the switch (8) is momentarily openedand closed by a protuberance 59 as any slider 48 is moved and thereby isopen at the moment a speed selector switch, including switch (7 is beingopened or closed by the sliders.

Although a preferred embodiment has been illustrated for the economicaluse of four sliders with a heavy switch (8), a fifth slider 48E can beprovided as illustrated in FIG. 10 in connection with FIG. 9 whereby thespring crank 74 need only actuate one slider. ln this embodiment themain switch (8) is preferably provided and it is the only switch thatneed be actuated by the spring 76. Slider 48E and switch (8) is alsoactuated by the OFF button, if desired. With the permutations ofswitches (l) to (7) the switch (8) is always closed whenever anypushbutton 2 to 8 for speed selection switches (1) to (7 is pressed andit is opened when the OFF pushbutton is pressed. Once the switch (8) isclosed then with movement of any of the four sliders the protuberancesin recesses 59 will open the switch (8) momentarily while a permutationof the speed switches is being changed.

However, whenever the tension of the spring 76 is applied to slider 485by the selector button 84, the slider will normally be urged and held tothe left as viewed in FIG. 10 unless a speed selection button is pressedand then only during the time that it is manually held depressed will itbe closed to provide the jogging function already mentioned.

Otherwise the general characteristics of the four sliders 48A, 48B, 48Cand 48D of FIG. 7 are substantially the same as those described whenslider 48E is present. I

Having thus described the structure and operation of several embodimentsof the invention other and further changes and modification can be madewithout departing from the inventive concept involving selectivelyrunning and jogging an appliance with the same speed selectionpushbuttons of a multipushbutton permutation switch.

What is claimed is:

1. In a speed control for a fractional-horsepower universal motor havinga plurality of cowound field coils of different impedances on thestator, the combination of:

circuit means including a first switch having a normally closed, movableconductor between two of the coils to connect the coils in seriesbetween one side of a power source and the motor armature;

a connection between the two coils including a second switch having anormally closed, movable conductor to shunt one of the coils and saidfirst switch;

a connection between the two coils including a third switch having anormally closed, movable conductor to shunt the other one of the coilsand said first switch;

switch control means for manually controlling said switch conductors forselected permutations of said field coils to provide a speed range ofvarious impedances and including actuator means for opening said first,second, and third switch conductors concurrently; and

selector means including a resilient element and manually movable to oneposition to resiliently urge said actuator means to open said first,second and third switch conductors when any of said movable conductorsclosing same are released from manual actuation.

2. The combination called for in claim 1 in which said switch controlmeans includes another actuator means for closing one of said second andthird switch conductors and opening the other one of said second andthird switch conductors and said first switch conductor concurrently.

3. The combination called for in claim 2 in which the firstmentionedactuator means controlling said switch conductors opens said one of thesecond and third switch conductors concurrently with the opening of saidthird and said other of said switch conductors.

4. The combination called for in claim 1 including a fourth switchhaving a normally closed, movable conductor connected in series withsaid three switches;

said selector means urging said actuator means to open said fourthswitch.

5. The combination called for in claim 4 in which said fourth switch isopened in timed sequential relationship following the opening of saidthree switches.

6. The combination called for in claim 2 in which said actuator meanscomprises:

a pair of switch control sliders independently movable between alternatepositions to provide the permutations of said switch closurescooperatively.

7. The combination called for in claim 6 in which two cams for eachslider are oppositely inclined, each at two of three switch stationsseparately and oppositely inclined at the common one of the three switchstations; 7

one of said sliders having cams to close the second and third switchconductors while opening the'first switch conductor with movement in onedirection and opening the second and third switch conductors whileclosing said first switch conductor with movement in the otherdirection;

the other one of said sliders having cams coordinated with the movementof said first slider to alternately open and close said third switchconductor when said second switch conductor is closed, and toalternately open and close said first switch conductor when said secondand third switch conductors are open.

8. In a speed control circuit for universal motors powered byalternating current the combination of:

a plurality of field coils of predetermined electrical impedances;

manually actuated switching means in said circuit including a pluralityof switches for interconnecting the coils in various permutations tovary the composite effective impedance for the motor field and includingone permutation which opens the circuit; and

manually actuated selector means including a resilient element andmovable between two position to resiliently urge in one position saidswitching means to said one permutation to open said circuit when saidswitching means is released from manual actuation.

9. The combination called for in claim 8 in which said selector meansincludes a manually movable element;

said resilient element comprising a spring interengaging said manuallymovable element and said manually actuated switching means; and

said manually movable element varying the resilient force urging saidswitching means to open the circuit when said switching means ismanually released.

10. In an electrically powered appliance with current responsiveelements of predetermined impedances:

a control switch means including a plurality of switch elements forselectively connecting said elements to a source of electrical power;

switch-actuating means having a permutation disposing said switchelements in an OFF condition including;

a control element movable between two positions one of which is aswitch-opening position and the other a switchelosing position;

a manually advanced element to move said control element to saidswitch-closing position and when manually released permit said controlelement to remain in said switch-closing position and to hold the switchclosed for energizing at least one of said current responsive elements;and

manually selective means including a releasable resilient elementmanually actuated to urge said control element to its switch-openingposition when said control element is free to so move.

11. The combination called for in claim 10 including another manuallyadvanced element to move said control element to its switch openingposition.

12. The combination called for in claim 10 in which said plurality ofswitches comprise three switches and said control means comprises tworeciprocable control elements actuating said three switches to providefour switch permutations in one of which the three switches are openposition to deencrgize said appliances, said selective means urging saidcontrol elements to said one permutation position.

13. The combination called for in claim 10 in which said plurality ofswitches comprise four switches and said control means comprises atleast two rcciprocable control elements actuating three of said switchesto provide four switch permutations in which three permutations are thesame and include the fourth switch;

switch means in series with said four switches for varying theimpedances controlled by said three switches and opening said fourthswitch means; and

a halfwave rectifier connected in parallel with said fourth switch.

14. In an electrical powered appliance having an impedance factor:

a permutation switch including a switch selection means;

a plurality of switches for varying the impedance factor of saidappliance;

said switch selection means including control means movable between aplurality of switch permutation positions one of which is aswitch-opening position;

a manually advanced element to move said control means to the otherposition and leave it there to close said switch and energize saidappliance; and

selective means movable between two positions to apply a resilient forcein one of said positions to said control means to return it from saidother position to its OFF position when said manually movable element isfree of manual restraint.

15. In an electrical powered appliance having an impedance factor:

a permutation switch including a switch selection means;

a plurality of switches for varying the impedance factor of saidappliance;

said switch selection means including control means movable between aplurality of switch permutation positions one of which is aswitch-opening position;

a manually advanced element to move said control means to the otherposition and leave it there to close said switch and energize saidappliance; and

selective means manually movable between two positions in one of whichit applies a resilient force to said control means to return it fromsaid other position to its OFF position when said manually movableelement is free of manual restraint.

1. In a speed control for a fractional-horsepower universal motor havinga plurality of cowound field coils of different impedances on thestator, the combination of: circuit means including a first switchhaving a normally closed, movable conductor between two of the coils toconnect the coils in series between one side of a power source and themotor Armature; a connection between the two coils including a secondswitch having a normally closed, movable conductor to shunt one of thecoils and said first switch; a connection between the two coilsincluding a third switch having a normally closed, movable conductor toshunt the other one of the coils and said first switch; switch controlmeans for manually controlling said switch conductors for selectedpermutations of said field coils to provide a speed range of variousimpedances and including actuator means for opening said first, second,and third switch conductors concurrently; and selector means including aresilient element and manually movable to one position to resilientlyurge said actuator means to open said first, second and third switchconductors when any of said movable conductors closing same are releasedfrom manual actuation.
 2. The combination called for in claim 1 in whichsaid switch control means includes another actuator means for closingone of said second and third switch conductors and opening the other oneof said second and third switch conductors and said first switchconductor concurrently.
 3. The combination called for in claim 2 inwhich the first-mentioned actuator means controlling said switchconductors opens said one of the second and third switch conductorsconcurrently with the opening of said third and said other of saidswitch conductors.
 4. The combination called for in claim 1 including afourth switch having a normally closed, movable conductor connected inseries with said three switches; said selector means urging saidactuator means to open said fourth switch.
 5. The combination called forin claim 4 in which said fourth switch is opened in timed sequentialrelationship following the opening of said three switches.
 6. Thecombination called for in claim 2 in which said actuator meanscomprises: a pair of switch control sliders independently movablebetween alternate positions to provide the permutations of said switchclosures cooperatively.
 7. The combination called for in claim 6 inwhich two cams for each slider are oppositely inclined, each at two ofthree switch stations separately and oppositely inclined at the commonone of the three switch stations; one of said sliders having cams toclose the second and third switch conductors while opening the firstswitch conductor with movement in one direction and opening the secondand third switch conductors while closing said first switch conductorwith movement in the other direction; the other one of said slidershaving cams coordinated with the movement of said first slider toalternately open and close said third switch conductor when said secondswitch conductor is closed, and to alternately open and close said firstswitch conductor when said second and third switch conductors are open.8. In a speed control circuit for universal motors powered byalternating current the combination of: a plurality of field coils ofpredetermined electrical impedances; manually actuated switching meansin said circuit including a plurality of switches for interconnectingthe coils in various permutations to vary the composite effectiveimpedance for the motor field and including one permutation which opensthe circuit; and manually actuated selector means including a resilientelement and movable between two position to resiliently urge in oneposition said switching means to said one permutation to open saidcircuit when said switching means is released from manual actuation. 9.The combination called for in claim 8 in which said selector meansincludes a manually movable element; said resilient element comprising aspring interengaging said manually movable element and said manuallyactuated switching means; and said manually movable element varying theresilient force urging said switching means to open the circuit whensaid switching means is manually released.
 10. In an electricallypowered appLiance with current responsive elements of predeterminedimpedances: a control switch means including a plurality of switchelements for selectively connecting said elements to a source ofelectrical power; switch-actuating means having a permutation disposingsaid switch elements in an OFF condition including; a control elementmovable between two positions one of which is a switch-opening positionand the other a switch-closing position; a manually advanced element tomove said control element to said switch-closing position and whenmanually released permit said control element to remain in saidswitch-closing position and to hold the switch closed for energizing atleast one of said current responsive elements; and manually selectivemeans including a releasable resilient element manually actuated to urgesaid control element to its switch-opening position when said controlelement is free to so move.
 11. The combination called for in claim 10including another manually advanced element to move said control elementto its switch opening position.
 12. The combination called for in claim10 in which said plurality of switches comprise three switches and saidcontrol means comprises two reciprocable control elements actuating saidthree switches to provide four switch permutations in one of which thethree switches are open position to deenergize said appliances, saidselective means urging said control elements to said one permutationposition.
 13. The combination called for in claim 10 in which saidplurality of switches comprise four switches and said control meanscomprises at least two reciprocable control elements actuating three ofsaid switches to provide four switch permutations in which threepermutations are the same and include the fourth switch; switch means inseries with said four switches for varying the impedances controlled bysaid three switches and opening said fourth switch means; and a halfwaverectifier connected in parallel with said fourth switch.
 14. In anelectrical powered appliance having an impedance factor: a permutationswitch including a switch selection means; a plurality of switches forvarying the impedance factor of said appliance; said switch selectionmeans including control means movable between a plurality of switchpermutation positions one of which is a switch-opening position; amanually advanced element to move said control means to the otherposition and leave it there to close said switch and energize saidappliance; and selective means movable between two positions to apply aresilient force in one of said positions to said control means to returnit from said other position to its OFF position when said manuallymovable element is free of manual restraint.
 15. In an electricalpowered appliance having an impedance factor: a permutation switchincluding a switch selection means; a plurality of switches for varyingthe impedance factor of said appliance; said switch selection meansincluding control means movable between a plurality of switchpermutation positions one of which is a switch-opening position; amanually advanced element to move said control means to the otherposition and leave it there to close said switch and energize saidappliance; and selective means manually movable between two positions inone of which it applies a resilient force to said control means toreturn it from said other position to its OFF position when saidmanually movable element is free of manual restraint.